static Key *
keygrab_ssh1(con *c)
{
static Key *rsa;
static Buffer msg;
if (rsa == NULL) {
buffer_init(&msg);
rsa = key_new(KEY_RSA1);
}
buffer_append(&msg, c->c_data, c->c_plen);
buffer_consume(&msg, 8 - (c->c_plen & 7)); /* padding */
if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) {
error("%s: invalid packet type", c->c_name);
buffer_clear(&msg);
return NULL;
}
buffer_consume(&msg, 8); /* cookie */
/* server key */
(void) buffer_get_int(&msg);
buffer_get_bignum(&msg, rsa->rsa->e);
buffer_get_bignum(&msg, rsa->rsa->n);
/* host key */
(void) buffer_get_int(&msg);
buffer_get_bignum(&msg, rsa->rsa->e);
buffer_get_bignum(&msg, rsa->rsa->n);
buffer_clear(&msg);
return (rsa);
}
static Key *
key_load_public_rsa1(int fd, const char *filename, char **commentp)
{
Buffer buffer;
Key *pub;
struct stat st;
char *cp;
int i;
off_t len;
if (fstat(fd, &st) < 0) {
error("fstat for key file %.200s failed: %.100s",
filename, strerror(errno));
return NULL;
}
len = st.st_size;
buffer_init(&buffer);
cp = buffer_append_space(&buffer, len);
if (read(fd, cp, (size_t) len) != (size_t) len) {
debug("Read from key file %.200s failed: %.100s", filename,
strerror(errno));
buffer_free(&buffer);
return NULL;
}
/* Check that it is at least big enough to contain the ID string. */
if (len < sizeof(authfile_id_string)) {
debug3("Not a RSA1 key file %.200s.", filename);
buffer_free(&buffer);
return NULL;
}
/*
* Make sure it begins with the id string. Consume the id string
* from the buffer.
*/
for (i = 0; i < sizeof(authfile_id_string); i++)
if (buffer_get_char(&buffer) != authfile_id_string[i]) {
debug3("Not a RSA1 key file %.200s.", filename);
buffer_free(&buffer);
return NULL;
}
/* Skip cipher type and reserved data. */
(void) buffer_get_char(&buffer); /* cipher type */
(void) buffer_get_int(&buffer); /* reserved */
/* Read the public key from the buffer. */
(void) buffer_get_int(&buffer);
pub = key_new(KEY_RSA1);
buffer_get_bignum(&buffer, pub->rsa->n);
buffer_get_bignum(&buffer, pub->rsa->e);
if (commentp)
*commentp = buffer_get_string(&buffer, NULL);
/* The encrypted private part is not parsed by this function. */
buffer_free(&buffer);
return pub;
}
Key *
ssh_get_next_identity(AuthenticationConnection *auth, char **comment, int version)
{
#ifdef WITH_SSH1
int keybits;
u_int bits;
#endif
u_char *blob;
u_int blen;
Key *key = NULL;
/* Return failure if no more entries. */
if (auth->howmany <= 0)
return NULL;
/*
* Get the next entry from the packet. These will abort with a fatal
* error if the packet is too short or contains corrupt data.
*/
switch (version) {
#ifdef WITH_SSH1
case 1:
key = key_new(KEY_RSA1);
bits = buffer_get_int(&auth->identities);
buffer_get_bignum(&auth->identities, key->rsa->e);
buffer_get_bignum(&auth->identities, key->rsa->n);
*comment = buffer_get_string(&auth->identities, NULL);
keybits = BN_num_bits(key->rsa->n);
if (keybits < 0 || bits != (u_int)keybits)
logit("Warning: identity keysize mismatch: actual %d, announced %u",
BN_num_bits(key->rsa->n), bits);
break;
#endif
case 2:
blob = buffer_get_string(&auth->identities, &blen);
*comment = buffer_get_string(&auth->identities, NULL);
key = key_from_blob(blob, blen);
free(blob);
break;
default:
return NULL;
}
/* Decrement the number of remaining entries. */
auth->howmany--;
return key;
}
static void
recv_rexec_state(int fd, Buffer *conf)
{
Buffer m;
char *cp;
u_int len;
debug3("%s: entering fd = %d", __func__, fd);
buffer_init(&m);
if (ssh_msg_recv(fd, &m) == -1)
fatal("%s: ssh_msg_recv failed", __func__);
if (buffer_get_char(&m) != 0)
fatal("%s: rexec version mismatch", __func__);
cp = buffer_get_string(&m, &len);
if (conf != NULL)
buffer_append(conf, cp, len + 1);
xfree(cp);
if (buffer_get_int(&m)) {
if (sensitive_data.server_key != NULL)
key_free(sensitive_data.server_key);
sensitive_data.server_key = key_new_private(KEY_RSA1);
buffer_get_bignum(&m, sensitive_data.server_key->rsa->e);
buffer_get_bignum(&m, sensitive_data.server_key->rsa->n);
buffer_get_bignum(&m, sensitive_data.server_key->rsa->d);
buffer_get_bignum(&m, sensitive_data.server_key->rsa->iqmp);
buffer_get_bignum(&m, sensitive_data.server_key->rsa->p);
buffer_get_bignum(&m, sensitive_data.server_key->rsa->q);
rsa_generate_additional_parameters(
sensitive_data.server_key->rsa);
}
buffer_free(&m);
debug3("%s: done", __func__);
}
static
int
is_dsakey_in_keyfile(DSA *dsa_1, char *host, char *filename)
{
FILE *fp = NULL;
char *line_buf = NULL;
char *str = NULL;
char *str_base64 = NULL;
Buffer keyfile_buf;
BIGNUM *bn_p = NULL;
BIGNUM *bn_q = NULL;
BIGNUM *bn_g = NULL;
BIGNUM *bn_pub_key = NULL;
int ret = 1;
size_t str_size = 0;
int i;
if (!dsa_1 || !host || !filename)
return 0;
memset(&keyfile_buf, 0, sizeof(keyfile_buf));
/* Open the keyfile */
if ( (fp = fopen(filename, "r")) == NULL) {
/* no key file */
ret = 1;
goto is_dsakey_in_keyfile_cleanup;
}
/* Get memory for a line buffer */
if ( (line_buf = pal_malloc(sizeof(char) * 4096)) == NULL) {
ret = 0;
goto is_dsakey_in_keyfile_cleanup;
}
while (freadline(line_buf, 4095, fp) != EOF) {
int len;
str_base64 = strtok(line_buf, " ");
if (strcmp(host, str_base64) != 0)
continue;
/* We got a match on the hostname
* Now we assemble a DSA object
* with what we have in the buffer
*/
str_base64 = strtok(NULL, " ");
if (strcmp("ssh-dss", str_base64) != 0)
continue;
/* We got a match on the key type as
well, going on
*/
str_base64 = strtok(NULL, " ");
/*
* Get the base64 data
* and discard ssh-dss first
*/
str_size = pal_strlen(str_base64) * sizeof(char);
if ( (str = pal_malloc(str_size)) == NULL) {
ret = 0;
goto is_dsakey_in_keyfile_cleanup;
}
if ( (len = base64decode(str, str_base64)) < 1) {
ret = 0;
goto is_dsakey_in_keyfile_cleanup;
}
/* Fill a buffer structure with this data
*/
buffer_init(&keyfile_buf);
if (keyfile_buf.buf == NULL) {
ret = 0;
goto is_dsakey_in_keyfile_cleanup;
}
buffer_append(&keyfile_buf, str, str_size);
/* Now get some BN filled with the data
* from the buffer and compare
* those with what we got in the incoming
* dsa object.
*/
bn_p = BN_new();
bn_q = BN_new();
bn_g = BN_new();
bn_pub_key = BN_new();
if (bn_p == NULL ||
bn_q == NULL ||
bn_g == NULL ||
bn_pub_key == NULL) {
ret = 0;
goto is_dsakey_in_keyfile_cleanup;
}
/* String is skipped XXX */
buffer_get_string(&keyfile_buf, (unsigned int*)&i); // Bogus i returns the string length, not used
buffer_get_bignum(&keyfile_buf, bn_p);
buffer_get_bignum(&keyfile_buf, bn_q);
buffer_get_bignum(&keyfile_buf, bn_g);
buffer_get_bignum(&keyfile_buf, bn_pub_key);
if ( !BN_cmp(dsa_1->p, bn_p) &&
!BN_cmp(dsa_1->q, bn_q) &&
!BN_cmp(dsa_1->g, bn_g) &&
!BN_cmp(dsa_1->pub_key, bn_pub_key) )
ret = 2;
else ret = 3;
}
is_dsakey_in_keyfile_cleanup:
if (str)
pal_free(str);
if (line_buf)
pal_free(line_buf);
if (fp)
fclose(fp);
if (bn_p)
BN_clear_free(bn_p);
if (bn_q)
BN_clear_free(bn_q);
if (bn_g)
BN_clear_free(bn_g);
if (bn_pub_key)
BN_clear_free(bn_pub_key);
if (keyfile_buf.buf)
buffer_free(&keyfile_buf);
return ret;
}
/** Add a DSA key to the tspc key file
*
* @param dsa the DSA param pointer filled with our key info
* @param host the hostname of the corresponding broker
* @param filename the keyfile to use
*
* @return 0 if error
* 1 if ok
*
*/
int
add_dsakey_to_keyfile(DSA *dsa, char *host, char *filename, tBoolean autoaccept)
{
FILE *fp = NULL;
Buffer buf;
char *str = NULL;
int ret = 0;
switch (is_dsakey_in_keyfile(dsa, host, filename)) {
case 0:
Display(LOG_LEVEL_3, ELInfo, TSP_AUTH_PASSDSS_STRING, GOGO_STR_ERR_IN_KEY_VERIF);
Display(LOG_LEVEL_3, ELWarning, TSP_AUTH_PASSDSS_STRING, GOGO_STR_SERVER_KEY_REJECTED);
break;
case 1: /* not in, we add and continue */
#if defined(WIN32) && !defined(WINCE)
// When running as a service we can't ask user
// permission. Compromise and accept the key auto
//
if (!IsService && !autoaccept)
{
#else
if (!autoaccept)
{
#endif
if (!ask(GOGO_STR_UNKNOWN_HOST_ADD_KEY, host))
{
Display(LOG_LEVEL_3, ELWarning, TSP_AUTH_PASSDSS_STRING, GOGO_STR_SERVER_KEY_REJECTED_USER);
break;
}
}
else
Display(LOG_LEVEL_1, ELWarning, TSP_AUTH_PASSDSS_STRING, GOGO_STR_WARN_SERVER_KEY_AUTO_ADDED);
Display(LOG_LEVEL_2, ELInfo, TSP_AUTH_PASSDSS_STRING, GOGO_STR_SERVER_KEY_ACCEPTED_ADDED);
buffer_init(&buf);
if (buf.buf == NULL)
break;
buffer_put_cstring(&buf, "ssh-dss");
buffer_put_bignum(&buf, dsa->p);
buffer_put_bignum(&buf, dsa->q);
buffer_put_bignum(&buf, dsa->g);
buffer_put_bignum(&buf, dsa->pub_key);
if ( (str = pal_malloc(2 * buffer_len(&buf))) == NULL)
break;
if ( (base64encode(str, buffer_ptr(&buf), (int) buffer_len(&buf))) < 1)
break;
fp = fopen(filename, "a");
if (fp) {
fprintf(fp, "%s ssh-dss %s\n", host, str);
fclose(fp);
ret = 1;
}
buffer_free(&buf);
pal_free(str);
break;
case 2: /* in and matching correctly, hurray */
Display(LOG_LEVEL_2, ELInfo, TSP_AUTH_PASSDSS_STRING, GOGO_STR_MATCHING_KEY_FOUND_USED);
ret = 1;
break;
case 3: /* in and NOT matching correctly */
Display(LOG_LEVEL_1, ELError, TSP_AUTH_PASSDSS_STRING, GOGO_STR_WARN_STORED_LOCAL_KEY_NO_MATCH, filename, host);
Display(LOG_LEVEL_3, ELWarning, TSP_AUTH_PASSDSS_STRING, GOGO_STR_SERVER_KEY_REJECTED);
ret = 0;
break;
}
return ret;
}
/**
* Authenticate to the Migration Broker using PASSDSS-3DES-1
*
* Buf_H will contain the data used to validate the server
* signature. The data is a concatenation of the following parameters,
* in that order:
* azname,authname,DH_public_key,pklength,"ssh-dss",p,q,g,z,Y,ssecmask,sbuflen,dh_K
*
* @param socket
* @param user
* @param passwd
* @param host
* @param nt
*
* @return
*
* @todo DH public key validation (RFC2631, 2.1.5)
* @todo Local storage for server public keys
*
*/
gogoc_status AuthPASSDSS_3DES_1(pal_socket_t socket, net_tools_t *nt, tConf *conf, tBrokerList **broker_list)
{
DH *dh = NULL; /**< client DH key used to exchange key with server */
DSA *dsa = NULL; /**< Remote server DSA key public information */
DSA_SIG *sig = NULL; /**< DSA signature */
char authenticate[] = "AUTHENTICATE PASSDSS-3DES-1\r\n";
char *BufferIn = NULL;
char *BufferOut = NULL;
char *BufferPtr = NULL;
Buffer BufH; /**< Buffer to hold data used for signature. */
Buffer BufSpace; /**< Space to hold data before/after base64 conversion */
Buffer *Buf_H = &BufH;
Buffer *Buf_Space = &BufSpace;
BIO *bio_rw = NULL; /**< Memory buffer bio */
BIO *b64= NULL; /**< Base64 bio */
BIO *cipher = NULL; /**< Symmetric crypto bio */
BIGNUM *server_pubkey = NULL; /**< received server public DH key */
BIGNUM *dh_K = NULL; /**< DH computed shared secret */
u_char hash[20]; /**< SHA1 hash */
u_char enc_key[24]; /**< encryption key (3des) */
u_char enc_iv[8]; /**< initialization vector (3des) */
u_char int_key[20]; /**< cs integrity key */
u_char tmphash[40]; /**< temporary hash storage */
u_char hmac[EVP_MAX_MD_SIZE]; /**< HMAC for integrity of sent data (step L) */
int pklength = 0; /**< length of SSH-style DSA server public key */
int ssecmask = 0; /**< SASL security layers offered */
int sbuflen = 0; /**< maximum server security layer block size */
char *s = NULL;
u_char num[3]; /**< Array to manupulate 3 octet number (sbuflen) */
/* Temporary variables */
int buflen, readlen, keysize, siglength;
gogoc_status status = STATUS_SUCCESS_INIT;
sint32_t tsp_status;
/* From draft-newman-sasl-passdss-01. "This group was taken from the
* ISAKMP/Oakley specification, and was originally generated by
* Richard Schroeppel at the University of Arizona. Properties of
* this prime are described in [Orm96]"
*/
/* RFC2409, DH group 2 (second Oakley group) */
static char *dh_group2=
"FFFFFFFF" "FFFFFFFF" "C90FDAA2" "2168C234" "C4C6628B" "80DC1CD1"
"29024E08" "8A67CC74" "020BBEA6" "3B139B22" "514A0879" "8E3404DD"
"EF9519B3" "CD3A431B" "302B0A6D" "F25F1437" "4FE1356D" "6D51C245"
"E485B576" "625E7EC6" "F44C42E9" "A637ED6B" "0BFF5CB6" "F406B7ED"
"EE386BFB" "5A899FA5" "AE9F2411" "7C4B1FE6" "49286651" "ECE65381"
"FFFFFFFF" "FFFFFFFF";
static unsigned char dh_g[]={
0x02,
};
/* Initialize Diffie Hellman variables */
if ((dh = DH_new()) == NULL || (server_pubkey = BN_new()) == NULL)
{
Display(LOG_LEVEL_1, ELError, TSP_AUTH_PASSDSS_STRING, STR_GEN_MALLOC_ERROR);
status = make_status(CTX_TSPAUTHENTICATION, ERR_MEMORY_STARVATION);
goto error;
}
/* Convert dh_group2 and dh_g to BIGNUM type */
BN_hex2bn(&dh->p, dh_group2);
dh->g = BN_bin2bn(dh_g,sizeof(dh_g),NULL);
if ((dh->p == NULL) || (dh->g == NULL))
{
Display(LOG_LEVEL_1, ELError, TSP_AUTH_PASSDSS_STRING, GOGO_STR_INITIALIZATION_ERROR);
status = make_status(CTX_TSPAUTHENTICATION, ERR_AUTHENTICATION_FAILURE);
goto error;
}
if ((dh_K = BN_new()) == NULL)
{
Display(LOG_LEVEL_1, ELError, TSP_AUTH_PASSDSS_STRING, STR_GEN_MALLOC_ERROR);
status = make_status(CTX_TSPAUTHENTICATION, ERR_MEMORY_STARVATION);
goto error;
}
/* Reserve storage for DSA key */
if ((dsa = DSA_new()) == NULL || (dsa->p = BN_new()) == NULL ||
(dsa->q = BN_new()) == NULL || (dsa->g = BN_new()) == NULL ||
(dsa->pub_key = BN_new()) == NULL || (dsa->priv_key = BN_new()) == NULL)
{
Display(LOG_LEVEL_1, ELError, TSP_AUTH_PASSDSS_STRING, STR_GEN_MALLOC_ERROR);
status = make_status(CTX_TSPAUTHENTICATION, ERR_MEMORY_STARVATION);
goto error;
}
/* Allocate memory for DSA signature */
if ((sig = DSA_SIG_new()) == NULL)
{
Display(LOG_LEVEL_1, ELError, TSP_AUTH_PASSDSS_STRING, STR_GEN_MALLOC_ERROR);
status = make_status(CTX_TSPAUTHENTICATION, ERR_MEMORY_STARVATION);
goto error;
}
/* Initialize data buffers */
BufferIn = calloc(1, TSP_AUTH_PASSDSS_BUFFERSIZE);
BufferOut = calloc(1, TSP_AUTH_PASSDSS_BUFFERSIZE);
if ((BufferIn == NULL) || (BufferOut == NULL))
{
Display(LOG_LEVEL_1, ELError, TSP_AUTH_PASSDSS_STRING, STR_GEN_MALLOC_ERROR);
status = make_status(CTX_TSPAUTHENTICATION, ERR_MEMORY_STARVATION);
goto error;
}
buffer_init(Buf_Space);
buffer_init(Buf_H);
if (Buf_Space->buf == NULL || Buf_H->buf == NULL)
{
Display(LOG_LEVEL_1, ELError, TSP_AUTH_PASSDSS_STRING, STR_GEN_MALLOC_ERROR);
status = make_status(CTX_TSPAUTHENTICATION, ERR_MEMORY_STARVATION);
goto error;
}
/* Create a read/write memory BIO. Memory is segment is
* created and resized as needed. When BIO is destroyed, the
* memory is freed. */
bio_rw = BIO_new(BIO_s_mem());
/* Create a base64 BIO filter */
b64 = BIO_new(BIO_f_base64());
if ((bio_rw == NULL) || (b64 == NULL))
{
Display(LOG_LEVEL_1, ELError, TSP_AUTH_PASSDSS_STRING, STR_GEN_MALLOC_ERROR);
status = make_status(CTX_TSPAUTHENTICATION, ERR_MEMORY_STARVATION);
goto error;
}
/*
Compute the Diffie-Hellman public value "X" as follows. If
X has a value of 0, repeat.
x
X = g mod n
where g = dh_g = 2
n = dh_group2
x = DH secret key
X = DH public key
*/
if (DH_generate_key(dh) == 0)
{
Display(LOG_LEVEL_1, ELError, TSP_AUTH_PASSDSS_STRING, GOGO_STR_DH_GEN_ERROR);
status = make_status(CTX_TSPAUTHENTICATION, ERR_AUTHENTICATION_FAILURE);
goto error;
}
/* Validate DH public key (RFC2631, 2.1.5) */
/* Send message with SASL mechanism identifier */
if ( nt->netsend(socket, authenticate, sizeof(authenticate)) == -1 )
{
Display(LOG_LEVEL_1, ELError, TSP_AUTH_PASSDSS_STRING, STR_NET_FAIL_W_SOCKET);
status = make_status(CTX_TSPAUTHENTICATION, ERR_SOCKET_IO);
goto error;
}
/* First PASSDSS message from client to server:
string azname ; the user name to login as, may be empty if
same as authentication name
string authname ; the authentication name
mpint X ; Diffie-Hellman parameter X
*/
/* azname is empty. Just insert a string length zero */
buffer_put_int(Buf_Space, 0);
/* authname */
buffer_put_cstring(Buf_Space, conf->userid);
/* DH public key */
buffer_put_bignum(Buf_Space, dh->pub_key);
/* At this point, save the buffer into Buf_H. Used later for
* signature verification. */
buffer_append(Buf_H, buffer_ptr(Buf_Space), buffer_len(Buf_Space));
/* Push base64 filter */
BIO_push(b64, bio_rw);
/* no newline */
BIO_set_flags(b64, BIO_FLAGS_BASE64_NO_NL);
/* Write Buffer content into bio_rw. Buffer will be base64
* encoded. */
BIO_write(b64, buffer_ptr(Buf_Space), (int) buffer_len(Buf_Space));
BIO_flush(b64);
/* Get pointer to the result */
buflen = BIO_get_mem_data(bio_rw, &BufferPtr);
// Send data to server, save response in BufferIn.
if((readlen = nt->netsendrecv(socket,
BufferPtr, buflen,
BufferIn, TSP_AUTH_PASSDSS_BUFFERSIZE)) == -1)
{
Display(LOG_LEVEL_1, ELError, TSP_AUTH_PASSDSS_STRING, STR_NET_FAIL_RW_SOCKET);
status = make_status(CTX_TSPAUTHENTICATION, ERR_SOCKET_IO);
goto error;
}
/* remove base64 filter */
BIO_pop(bio_rw);
buffer_clear(Buf_Space);
buflen = 0;
/* Decode response (base64) and extract server response
*
* The response format is as follows:
uint32 pklength ; length of SSH-style DSA server public key
(number of bytes up to y, inclusively)
string "ssh-dss" ; constant string "ssh-dss" (lower case)
mpint p ; DSA public key parameters
mpint q
mpint g
mpint z (y in draft)
mpint Y ; Diffie-Hellman parameter Y
OCTET ssecmask ; SASL security layers offered
3 OCTET sbuflen ; maximum server security layer block size
uint32 siglength ; length of SSH-style dss signature
(number of bytes up to s inclusively)
string "ssh-dss" ; constant string "ssh-dss" (lower case)
mpint r ; DSA signature parameters
mpint s
*/
buflen = base64decode(BufferOut, BufferIn);
buffer_append(Buf_Space, BufferOut, buflen);
/* Get pklength */
pklength = buffer_get_int(Buf_Space);
/* Assuming that
* p, g, and y are 512 bits,
* q is 160 bits,
* "ssh-dss" is 7 bytes
* pklength should be at least 240 bytes.
*/
if (pklength < 240)
{
Display(LOG_LEVEL_1, ELError, TSP_AUTH_PASSDSS_STRING, GOGO_STR_RCVD_DATA_INVALID);
status = make_status(CTX_TSPAUTHENTICATION, ERR_AUTHENTICATION_FAILURE);
goto error;
}
/* Make a copy of (pklength|"ssh-dss"|p|q|g|z) in Buf_H */
/* Add pklength */
buffer_put_int(Buf_H, pklength);
/* Add "ssh-dss"|p|q|g|z */
buffer_append(Buf_H, buffer_ptr(Buf_Space), pklength);
/* Get "ssh-dss" string */
s = buffer_get_string(Buf_Space, (unsigned int*)&buflen);
pal_free(s); s = NULL;
/* Get p */
buffer_get_bignum(Buf_Space, dsa->p);
/* Get q */
buffer_get_bignum(Buf_Space, dsa->q);
/* Get g */
buffer_get_bignum(Buf_Space, dsa->g);
/* Get z (pub_key) */
buffer_get_bignum(Buf_Space, dsa->pub_key);
/* Get DH public key */
buffer_get_bignum(Buf_Space, server_pubkey);
/* Copy in Buf_H for signature verification later */
buffer_put_bignum(Buf_H, server_pubkey);
/* Buffer now points at ssecmask (1 octet), followed by
* sbuflen (3 octets). Make a copy of these 4 octets in Buf_H
* now, then extract these values. */
buffer_append(Buf_H, buffer_ptr(Buf_Space), 4);
/* Get ssecmask */
ssecmask = buffer_get_octet(Buf_Space);
/* Get sbuflen
* Big endian binary unsigned integer */
buffer_get(Buf_Space, (char *)num, 3);
sbuflen = (((u_long)(u_char)(num)[0] << 16) |
((u_long)(u_char)(num)[1] << 8) |
((u_long)(u_char)(num)[2]));
/* DSS signature */
/* Get siglength */
siglength = buffer_get_int(Buf_Space);
/* r and s are 20 bytes each, encoded as mpint (2*24)
* "ssh-dss" is 7 bytes + int32 siglength should be >= 59
* octets (mpint may have leading zero byte)
*/
if (siglength < 59)
{
Display(LOG_LEVEL_1, ELError, TSP_AUTH_PASSDSS_STRING, GOGO_STR_RCVD_DATA_INVALID);
status = make_status(CTX_TSPAUTHENTICATION, ERR_AUTHENTICATION_FAILURE);
goto error;
}
/* Get "ssh-dss" string */
s = buffer_get_string(Buf_Space, (unsigned int*)&buflen);
pal_free(s); s = NULL;
/* Get DSA signature r and s*/
if ((sig->r= BN_new()) == NULL || (sig->s = BN_new()) == NULL)
{
Display(LOG_LEVEL_1, ELError, TSP_AUTH_PASSDSS_STRING, STR_GEN_MALLOC_ERROR);
status = make_status(CTX_TSPAUTHENTICATION, ERR_MEMORY_STARVATION);
goto error;
}
/* Get r */
buffer_get_bignum(Buf_Space, sig->r);
/* Get s */
buffer_get_bignum(Buf_Space, sig->s);
/* Validate server DH public key (RFC2631, 2.1.5) */
{
if( !add_dsakey_to_keyfile(dsa, conf->server, TSPC_DSA_KEYFILE, conf->no_questions) )
{
Display(LOG_LEVEL_1, ELError, TSP_AUTH_PASSDSS_STRING, GOGO_STR_KEY_VERIF_ERROR);
status = make_status(CTX_TSPAUTHENTICATION, ERR_AUTHENTICATION_FAILURE);
goto error;
}
}
/* Verify that DSA public key belongs to server */
/* Compute DH shared secret */
if ((s = calloc(1, DH_size(dh))) == NULL)
{
Display(LOG_LEVEL_1, ELError, TSP_AUTH_PASSDSS_STRING, STR_GEN_MALLOC_ERROR);
status = make_status(CTX_TSPAUTHENTICATION, ERR_MEMORY_STARVATION);
goto error;
}
if( (keysize = DH_compute_key((unsigned char*)s, server_pubkey, dh)) < 0 )
{
Display(LOG_LEVEL_1, ELError, TSP_AUTH_PASSDSS_STRING, GOGO_STR_DH_SHARED_COMPUTE_ERROR);
status = make_status(CTX_TSPAUTHENTICATION, ERR_AUTHENTICATION_FAILURE);
goto error;
}
BN_bin2bn((const unsigned char*)s, keysize, dh_K);
memset(s, 0, keysize);
pal_free(s);
s = NULL;
Display(LOG_LEVEL_3, ELDebug, TSP_AUTH_PASSDSS_STRING,
GOGO_STR_DH_SHARED_KEY, BN_bn2hex(dh_K));
/* Append dh_K in to complete the buffer. Use Buffer to hold
* result to keep Bf_H intact, since to will be used (without
* dh_K) to compute HMAC for packet integrity. */
buffer_clear(Buf_Space);
buffer_append(Buf_Space, buffer_ptr(Buf_H), buffer_len(Buf_H));
buffer_put_bignum(Buf_Space, dh_K);
/* Compute SHA1 hash of Buffer */
SHA1(buffer_ptr(Buf_Space), buffer_len(Buf_Space), hash);
/* Debug information available at level 4 */
{
BIGNUM *h;
h = BN_bin2bn(hash, 20, NULL);
Display(LOG_LEVEL_3, ELDebug, TSP_AUTH_PASSDSS_STRING,
GOGO_STR_SIGNED_HASH, BN_bn2hex(h));
BN_free(h);
}
Display(LOG_LEVEL_3, ELDebug, TSP_AUTH_PASSDSS_STRING,
GOGO_STR_DSA_SIGN_R, BN_bn2hex(sig->r));
Display(LOG_LEVEL_3, ELDebug, TSP_AUTH_PASSDSS_STRING,
GOGO_STR_DSA_SIGN_S, BN_bn2hex(sig->s));
// Verify that the DSS signature is a signature of hash.
switch( DSA_do_verify(hash, sizeof(hash), sig, dsa) )
{
case 0:
Display(LOG_LEVEL_1, ELError, TSP_AUTH_PASSDSS_STRING, GOGO_STR_BAD_SIG_FROM_SERVER);
status = make_status(CTX_TSPAUTHENTICATION, ERR_AUTHENTICATION_FAILURE);
goto error;
break; /* NOTREACHED */
case 1: /* correct signature */
break;
default: /* -1 on error */
Display(LOG_LEVEL_1, ELError, TSP_AUTH_PASSDSS_STRING, GOGO_STR_SIG_VERIF_ERROR);
status = make_status(CTX_TSPAUTHENTICATION, ERR_AUTHENTICATION_FAILURE);
goto error;
break; /* NOTREACHED */
}
/* Step I: Compute 3DES key and iv */
/*
cs-encryption-iv = SHA1( K || "A" || H )
sc-encryption-iv = SHA1( K || "B" || H )
cs-encryption-key-1 = SHA1( K || "C" || H )
cs-encryption-key-2 = SHA1( K || cs-encryption-key-1 )
cs-encryption-key = cs-encryption-key-1 || cs-encryption-key-2
sc-encryption-key-1 = SHA1( K || "D" || H )
sc-encryption-key-2 = SHA1( K || sc-encryption-key-1 )
sc-encryption-key = sc-encryption-key-1 || sc-encryption-key-2
cs-integrity-key = SHA1( K || "E" || H )
sc-integrity-key = SHA1( K || "F" || H )
K is dh_k in mpint format (string)
H is hash
*/
/* Since we won't support SASL security layers, we need to
* compute the following only:
* cs-encryption-iv
* cs-encryption-key
* cs-integrity-key
*/
buffer_clear(Buf_Space);
buffer_put_bignum(Buf_Space, dh_K);
buffer_put_octet(Buf_Space,'A');
buffer_append(Buf_Space, hash, 20);
SHA1(buffer_ptr(Buf_Space), buffer_len(Buf_Space), tmphash);
/* Use first 8 octets as iv */
memcpy(enc_iv, tmphash, 8);
buffer_clear(Buf_Space);
buffer_put_bignum(Buf_Space, dh_K);
buffer_put_octet(Buf_Space,'E');
buffer_append(Buf_Space, hash, 20);
SHA1(buffer_ptr(Buf_Space), buffer_len(Buf_Space), int_key);
buffer_clear(Buf_Space);
buffer_put_bignum(Buf_Space, dh_K);
buffer_put_octet(Buf_Space,'C');
buffer_append(Buf_Space, hash, 20);
SHA1(buffer_ptr(Buf_Space), buffer_len(Buf_Space), tmphash);
buffer_clear(Buf_Space);
buffer_put_bignum(Buf_Space, dh_K);
buffer_append(Buf_Space, tmphash, 20);
SHA1(buffer_ptr(Buf_Space), buffer_len(Buf_Space), tmphash+20);
/* Use first 24 octets as key */
memcpy(enc_key, tmphash, 24);
{
BIGNUM *enc, *i, *iv;
enc = BN_bin2bn(enc_key, 24, NULL);
iv = BN_bin2bn(enc_iv, 8, NULL);
i = BN_bin2bn(int_key, 20, NULL);
Display(LOG_LEVEL_3, ELDebug, TSP_AUTH_PASSDSS_STRING,
GOGO_STR_PASSDS_ENC_KEY, BN_bn2hex(enc));
Display(LOG_LEVEL_3, ELDebug, TSP_AUTH_PASSDSS_STRING,
GOGO_STR_PASSDS_IV, BN_bn2hex(iv));
Display(LOG_LEVEL_3, ELDebug, TSP_AUTH_PASSDSS_STRING,
GOGO_STR_PASSDS_INTEG_KEY, BN_bn2hex(i));
BN_free(enc);
BN_free(i);
BN_free(iv);
}
/*
(J) Create a buffer beginning with a bit mask for the
selected security layer (it MUST be one offered from server)
followed by three octets representing the maximum
cipher-text buffer size (at least 32) the client can accept
in network byte order. This is followed by a string
containing the passphrase.
*/
buffer_clear(Buf_Space);
buffer_put_octet(Buf_Space, ssecmask);
buffer_put_octet(Buf_Space, 0);
buffer_put_octet(Buf_Space, 0);
buffer_put_octet(Buf_Space, 0); /**< @bug must be at least 32 */
buffer_put_cstring(Buf_Space, conf->passwd);
/*
(K) Create a buffer containing items (1) through (7)
immediately followed by the first four octets of (J).
*/
buffer_append(Buf_H, buffer_ptr(Buf_Space), 4);
/*
(L) Compute HMAC-SHA-1 with (K) as the data and the
cs-integrity- key from step (I) as the key. This produces a
20 octet result.
*/
HMAC(EVP_sha1(), int_key, sizeof(int_key),
buffer_ptr(Buf_H), buffer_len(Buf_H), hmac, (unsigned int*)&keysize);
/*
(M) Create a buffer containing (J) followed by (L) followed
by an arbitrary number of zero octets as necessary to reach
the block size of DES and conceal the passphrase length from
an eavesdropper.
*/
buffer_append(Buf_Space, hmac, keysize);
/*
(N) Apply the triple-DES algorithm to (M) with the first 8
octets of cs-encryption-iv from step (I) as the
initialization vector and the first 24 octets of
cs-encryption-key as the key.
*/
/*
Padding is automatically done. From OpenSSL EVP_EncryptInit(3):
EVP_CIPHER_CTX_set_padding() enables or disables padding. By default
encryption operations are padded using standard block padding and the
padding is checked and removed when decrypting.
*/
/*
Create BIO filter to encrypt using 3des + convert to
base64. Result is written in memory BIO.
*/
/* Erase BIO and buffer memory */
BIO_reset(bio_rw);
memset(BufferOut, 0, TSP_AUTH_PASSDSS_BUFFERSIZE);
memset(BufferIn, 0, TSP_AUTH_PASSDSS_BUFFERSIZE);
buflen = 0;
/* Create cipher BIO */
cipher = BIO_new(BIO_f_cipher());
BIO_set_cipher(cipher, EVP_des_ede3_cbc(), enc_key, enc_iv, 1);
/* Assemble filters as cipher->b64->bio_rw */
BIO_push(cipher, b64);
BIO_push(b64, bio_rw);
/* Write Buffer content into bio_rw */
BIO_write(cipher, buffer_ptr(Buf_Space), (int) buffer_len(Buf_Space));
BIO_flush(cipher);
/* Get pointer to the result. */
buflen = BIO_get_mem_data(bio_rw, &BufferPtr);
/* wipe encryption material */
memset(enc_key, 0, sizeof(enc_key));
memset(enc_iv, 0, sizeof(enc_iv));
/* Send data to server, save response in BufferIn */
if( (readlen = nt->netsendrecv(socket, BufferPtr, buflen,
BufferIn, TSP_AUTH_PASSDSS_BUFFERSIZE)) == -1)
{
Display(LOG_LEVEL_1, ELError, TSP_AUTH_PASSDSS_STRING, STR_NET_FAIL_RW_SOCKET);
status = make_status(CTX_TSPAUTHENTICATION, ERR_SOCKET_IO);
goto error;
}
tsp_status = tspGetStatusCode(BufferIn);
// Check if the reply status indicated a broker redirection.
if( tspIsRedirectStatus(tsp_status) )
{
if( tspHandleRedirect(BufferIn, conf, broker_list) == TSP_REDIRECT_OK )
{
status = make_status(CTX_TSPAUTHENTICATION, EVNT_BROKER_REDIRECTION);
}
else
{
// Redirect error.
status = make_status(CTX_TSPAUTHENTICATION, ERR_BROKER_REDIRECTION);
}
goto error;
}
// Check if authentication was successful.
switch( tsp_status )
{
case TSP_PROTOCOL_SUCCESS:
break;
case TSP_PROTOCOL_AUTH_FAILED:
Display(LOG_LEVEL_1, ELError, "AuthPASSDSS_3DES_1", STR_TSP_AUTH_FAILED_USER, conf->userid);
status = make_status(CTX_TSPAUTHENTICATION, ERR_AUTHENTICATION_FAILURE);
goto error;
default:
Display(LOG_LEVEL_1, ELError, "AuthPASSDSS_3DES_1", STR_TSP_UNKNOWN_ERR_AUTH_FAILED, tspGetTspStatusStr(tsp_status));
status = make_status(CTX_TSPAUTHENTICATION, ERR_TSP_GENERIC_ERROR);
goto error;
}
status = STATUS_SUCCESS_INIT;
error:
/* Free storage for DSA key */
if (dsa != NULL) DSA_free(dsa); /* Also frees BIGNUMs inside struct */
/* DSA signature */
if (sig != NULL) DSA_SIG_free(sig);
/* Free Diffie Hellman variables */
if (dh != NULL) DH_free(dh); /* Also frees BIGNUMs inside struct */
if (server_pubkey != NULL) BN_free(server_pubkey);
if (dh_K != NULL) BN_free(dh_K);
/* Buffers */
if (Buf_Space->buf != NULL) buffer_free(Buf_Space);
if (Buf_H->buf != NULL) buffer_free(Buf_H);
/* malloc'ed space*/
if (BufferIn != NULL) pal_free(BufferIn);
if (BufferOut != NULL) pal_free(BufferOut);
/* BIOs */
if (cipher != NULL) BIO_vfree(cipher);
if (b64 != NULL) BIO_vfree(b64);
if (bio_rw != NULL) BIO_vfree(bio_rw);
/* strings buffers */
if (s != NULL) pal_free(s);
return status;
}
static Key *
key_load_private_rsa1(int fd, const char *filename, const char *passphrase,
char **commentp)
{
int i, check1, check2, cipher_type;
off_t len;
Buffer buffer, decrypted;
u_char *cp;
CipherContext ciphercontext;
Cipher *cipher;
Key *prv = NULL;
struct stat st;
if (fstat(fd, &st) < 0) {
error("fstat for key file %.200s failed: %.100s",
filename, strerror(errno));
close(fd);
return NULL;
}
len = st.st_size;
buffer_init(&buffer);
cp = buffer_append_space(&buffer, len);
if (read(fd, cp, (size_t) len) != (size_t) len) {
debug("Read from key file %.200s failed: %.100s", filename,
strerror(errno));
buffer_free(&buffer);
close(fd);
return NULL;
}
/* Check that it is at least big enough to contain the ID string. */
if (len < sizeof(authfile_id_string)) {
debug3("Not a RSA1 key file %.200s.", filename);
buffer_free(&buffer);
close(fd);
return NULL;
}
/*
* Make sure it begins with the id string. Consume the id string
* from the buffer.
*/
for (i = 0; i < sizeof(authfile_id_string); i++)
if (buffer_get_char(&buffer) != authfile_id_string[i]) {
debug3("Not a RSA1 key file %.200s.", filename);
buffer_free(&buffer);
close(fd);
return NULL;
}
/* Read cipher type. */
cipher_type = buffer_get_char(&buffer);
(void) buffer_get_int(&buffer); /* Reserved data. */
/* Read the public key from the buffer. */
(void) buffer_get_int(&buffer);
prv = key_new_private(KEY_RSA1);
buffer_get_bignum(&buffer, prv->rsa->n);
buffer_get_bignum(&buffer, prv->rsa->e);
if (commentp)
*commentp = buffer_get_string(&buffer, NULL);
else
xfree(buffer_get_string(&buffer, NULL));
/* Check that it is a supported cipher. */
cipher = cipher_by_number(cipher_type);
if (cipher == NULL) {
debug("Unsupported cipher %d used in key file %.200s.",
cipher_type, filename);
buffer_free(&buffer);
goto fail;
}
/* Initialize space for decrypted data. */
buffer_init(&decrypted);
cp = buffer_append_space(&decrypted, buffer_len(&buffer));
/* Rest of the buffer is encrypted. Decrypt it using the passphrase. */
cipher_set_key_string(&ciphercontext, cipher, passphrase,
CIPHER_DECRYPT);
cipher_crypt(&ciphercontext, cp,
buffer_ptr(&buffer), buffer_len(&buffer));
cipher_cleanup(&ciphercontext);
memset(&ciphercontext, 0, sizeof(ciphercontext));
buffer_free(&buffer);
check1 = buffer_get_char(&decrypted);
check2 = buffer_get_char(&decrypted);
if (check1 != buffer_get_char(&decrypted) ||
check2 != buffer_get_char(&decrypted)) {
if (strcmp(passphrase, "") != 0)
debug("Bad passphrase supplied for key file %.200s.",
filename);
/* Bad passphrase. */
buffer_free(&decrypted);
goto fail;
}
/* Read the rest of the private key. */
buffer_get_bignum(&decrypted, prv->rsa->d);
buffer_get_bignum(&decrypted, prv->rsa->iqmp); /* u */
/* in SSL and SSH v1 p and q are exchanged */
buffer_get_bignum(&decrypted, prv->rsa->q); /* p */
buffer_get_bignum(&decrypted, prv->rsa->p); /* q */
/* calculate p-1 and q-1 */
rsa_generate_additional_parameters(prv->rsa);
buffer_free(&decrypted);
/* enable blinding */
if (RSA_blinding_on(prv->rsa, NULL) != 1) {
error("key_load_private_rsa1: RSA_blinding_on failed");
goto fail;
}
close(fd);
return prv;
fail:
if (commentp)
xfree(*commentp);
close(fd);
key_free(prv);
return NULL;
}
